SB-1 grounding question

[Madcity Fats]

I have an old SB-1 that was kind of buzzy at the last gig I brought it to. I figured it was just the lights and the fact that these basses tend not to be all that well shielded.

However, when I opened it up just to be sure, the ground wire appears to run from the bridge to the output jack. I'm not so great at reading schematics, but on most diagrams I've seen it appears the ground should run from the bridge to the tone pot.

Did someone wire this incorrectly? Is there a big difference over grounding to the jack rather than the tone pot?

Everything else works fine otherwise, and ground hum does not appear to be an issue except for this one instance on stage. Is this just a shielding issue, or should I rewire the ground on this thing?

[TDR1138]

as long as the ground is from the bridge to the ground tab and not the positive tab on the jack, you should be ok. If the hum was a one-time issue, I wouldn't worry about it.

Did you try any other basses at the gig, and if so, were they quiet or buzz?

Shielding never hurt anybody either...

[Ken Baker]

Originally Posted by Madcity Fats

Did someone wire this incorrectly? Is there a big difference over grounding to the jack rather than the tone pot?

Nope - they did just fine. As TDR1138 said, you should be okay. On a simple circuit such as this, anywhere you can pick up a ground is fine. Theoretically, this should be a better ground location that a pot cover.

Everything else works fine otherwise, and ground hum does not appear to be an issue except for this one instance on stage. Is this just a shielding issue, or should I rewire the ground on this thing?

If this is a low-pitched 60 Hz hum with little or no high frequency component (think Strat single coils) with greatly reduced signal, you may have an open ground somewhere in your signal path. If there is a fair amount of high frequency junk, as in buzzing, look to lighting and power issues. Shielding your cavities may help.

Ken...

[Madcity Fats]

Sweet. I didn't think this should be an issue, but I'm no electronics whiz. Appreciate the confirmation (and man, I dig this place for quick answers like these).

The bass is perfectly quiet at practice (etc.) and my other basses don't seem to act up on that same stage, so I suspect some shielding is in order. That will be my next project, I suspect.